Leg prosthetic sleeve RFX® Flex

Product overview
ALPS RFX® Reinforced Flex Sleeve is a prosthetic knee sleeve combining grey or black outer fabric with an OptiGel interface and an extra internal fabric layer. Designed with a 30° pre‑flexion to reduce bunching behind the knee, the RFX supports secure suspension, improved control and enhanced durability for active users.

Key benefits

• Enhanced control of the prosthetic limb
• 30° pre‑flexion to ease knee flexion and reduce popliteal bunching
• Extra internal fabric layer for increased durability suitable for higher activity levels
• Secure suspension of the prosthetic leg

Technical details
Material

• OptiGel: ALPS exclusive white high‑density gel
• High Density Gel (HD Gel): relatively firm gel providing comfort with control and stability; suitable for transition from silicone liners
• OptiSil: latest white silicone option
• EasyGel: contains antioxidants; recommended for adherent scar tissue, skin irritation, sensitive skin and diabetic users
• GripGel: tacky gel to help reduce bunching in the popliteal area; recommended for amputees with healthy skin tissue
• Silicone

Fabric

• Grey fabric: highly reduced vertical stretch
• Black fabric: highly reduced vertical stretch
• Seamless knitted fabric: in‑house knitted fabric with high‑quality yarns
• Beige fabric: both horizontal and vertical stretch
• Brown fabric: reduced vertical stretch

Activity level

• k1: Low activity
• k2: Middle/low activity
• k3: Middle/high activity
• k4: High activity

Thickness

• Available thickness options: 2MM, 3MM, 6MM, 3/6MM and AP Tapered
• Typical listed option for RFX: 3MM

Cross section
Layered cross‑section design illustrating fabric, OptiGel layer and extra internal fabric for reinforcement and suspension performance.

RFX Reinforced Flex Sleeve — Sizing chart
MEASURED SIZE (CM) — 3 MM UNIFORM GREY FABRIC — 3 MM UNIFORM BLACK FABRIC
34-37 cm — RFX20-3G — RFX20-3BL
36-39 cm — RFX23-3G — RFX23-3BL
38-42 cm — RFX26-3G — RFX26-3BL
41-46 cm — RFX29-3G — RFX29-3BL
45-50 cm — RFX32-3G — RFX32-3BL

Technical characteristics / specifications

• Brand: ALPS
• Commercial name / model: RFX® Reinforced Flex Sleeve
• Pre‑flexion: 30° pre‑flexion construct to reduce behind‑knee bunching
• Primary interface material options: OptiGel, HD Gel, OptiSil, EasyGel, GripGel, Silicone
• Fabric options: Grey, Black, Beige, Brown; seamless knitted fabric variants
• Thickness options: 2MM, 3MM, 6MM, 3/6MM, AP Tapered (3MM commonly used)
• Activity levels supported: k1, k2, k3, k4
• Key features: extra internal fabric layer for reinforcement, secure suspension capability, reduced vertical stretch variants for improved control
• Sizing: circumference measured 10 cm above centre of knee; size codes correspond to ranges shown in sizing chart