This is not compatible with the 331B. The old one has 5 pins and this one has 6. It can be used in the 331B with modifications, but it won't recognize the temperature. This issue wasn't clear in the description. However, it's my fault, not the distributor's.

The order arrived in good condition, I appreciate the positive experience, The seller is excellent.

The gun is good and has strong suction. The tube arrived slightly damaged, which reduced the suction, but switching sides resolved the issue and restored normal suction. The sensor isn't working, likely due to being connected to 24-volt AC wires (black and blue),which may have damaged it.

Shipping was extremely fast, and I highly recommend this seller.