Maybe one of these similar products would be of interest:-

Sunny Health & Fitness Performance Treadmill Features Auto Incline, Dedicated Speed Buttons, Double Deck Technology, Digital Performance Display with BMI Calculator and Pulse Sensors

Guy-Tech AC DC Adapter Compatible with Proform 225 CSX PFEX529150 Stationary Bicycle; Proform 135 CSX PFEX519150 Stationary Bicycle Power Supply Cord

Treadmill Safety Key - Part No. 335158 - ProForm Performance 600i (PFTL795155)

Treadmill Safety Key | Part Number 301180 | Compatible with ProForm Performance 600 Treadmills

Sportsmith PreLubed Treadmill Belt fits certain ProForm Performance 400i*