The specific model sizes are not explicitly stated in Anthropic's accouncement, but some details about the context window size are given:
All three models will initially offer a 200K context window upon launch. It is mentioned that all three models are capable of accepting inputs exceeding 1 million tokens, and this may be made available to select customers who need enhanced processing power. So the exact model sizes are not provided, but we know that the models can handle context windows of at least 200,000 tokens, and potentially up to 1 million tokens for certain use cases. The document does not provide further specifics on the overall parameter counts or model sizes for the different variants of the Claude 3 model family.