Most safety interlocks in the market usually have up to 6 contacts which is more than required in many applications. The revised EN ISO 14119 standard requires two interlock devices to achieve PLe when using a Type 2 interlock device. For one of the two interlock devices, 2 contacts are sufficient. The HS5L is designed to with 2 or 4 contacts, and as a result, the overall size is reduced for more flexibility in installation.